Flotation process



Patented Jan. 14, 1930 JOSEPH H. LANE, OF VENICE, CALIFORNIA FLOTATION PROCESS N'o Drawing.

My invention relates to ore concentration processes and particularly to the flotation reagents used therein.

It is a purpose of my invention to provide an ore concentrating process which is characterized by eliminating the use of flotation oil and in its place employing a reagent which is extremely inexpensive yet highly eflicient in its ability to concentrate ores to the extent of greatly increasing the percentage of concent-rates recovered from a given quantity of ore.

In carrying out my invention, I employ Wood pulp in the form of fresh and undried sawdust procured from the sawing of any suitable wood such as pine, I having found by experimentation that sawdust possesses suflicient oil and other ingredients valuable in ore concentration which, when combined in proper proportions with other well known reagents, excepting oil, secures a higher percentage of mineral extraction than has been possible in any flotation process using oil.

In practicing my invention, I use from one to four pounds of fresh and undried pine sawdust to each ton of ore to be treated, the exact quantity of sawdust depending upon the amount of mineral in the heads to be lifted. Although I have found that using pine sawdust, as found in a sawmill, secures results superior to previous concentrating processes, a still higher degree of mineral recovery is attainable by grinding the sawdust to a higher degree of fineness, say minus 200 mesh, to reduce it to a pulp which liberates the flotation reagents therein so that when combined with other well known reagents and mixed with the ore to be treated, the mineral particles will exhibit a superior obtain a higher degree of extraction.

In the treatment of lead ore, for example, the sawdust is ground with the ore, and where the ore contains 6.8% lead per ton three pounds of sawdust are used to each ton,

together with 0.7 of a pound of cyanide,

0.7 of a pound of zinc sulphate, one pound of sodium bicarbonate and 0.1 of a pound of xanthate. During grinding both the ore and sawdust are reduced to the required dephysical attraction for the reagents and thus Application filed August 3, 1927. Serial No. 210,459.

gree of fineness and the resultant Wood pulp thoroughly mixed with the comminuted ore so that when the mass is finally delivered to the flotation machines and the fluid agitated the mineral particles are caused to adhere to the particles of wood pulp and thus floated leaving the mineral-free gangue particles capable of rejection. The mineral particles thus extracted can be subjected to the usual cleaning operations by which the flotation reagents are removed and the mineral particles left clean and free. I have found when using sawdust or wood pulp the ore does not require as much agitation as processes employing oil, and further a much cleaner froth is obtained. With crude lead ore containing 6.8% lead, the extraction is 84% of lead.

The efficiency of my process is exemplified in its adaptation to the lead tailings resultant of the above described process. By adding to the tailings about one-half pound of copper sulphate and one-fifth of a pound of xant-hate, 62.8% of zinc can be extracted from 7.5% crude zinc ore.

Although I have herein shown and described only one process of concentrating ores embodying my invention, it is to be understood that various changes and modifications may be made herein without departing from the spirit thereof and the spirit and scope of the appended claims.

I claim:

1. A process of concentrating ores by froth flotation which comprises reducing woo-d to a a pulp to liberate the flotation agents therein, combining the flotation agents thus secured with the mineral-bearing ore and chemical flotation agents devoid of oil and subjecting the resulting mixture to a flotation operation. 2. A process of concentrating ores by froth flotation which comprises adding fresh and undried comminuted wood together with chemical flotation agents containing no oil to the mineral-bearing ore, and subjecting the resulting mixture to a flotation operation JOSEPH H. LANE. 

